"ROME -- Major nations have failed to agree to set a goal halving greenhouse gas emissions by 2050, according to a draft document ahead of talks on Thursday -- a setback to efforts to secure a new U.N. climate pact.

Neogotiations involving senior officials from the 17-nation Major Economies Forum broke down overnight after China and India opposed any mention of the target, a source familiar with negotiations told Reuters.

They first want to see rich nations commit to making deep cuts in their own emissions by 2020 and they want developed nations to work out plans to provide developing nations with short-term finance to help them cope with ever more floods, heatwaves, storms and rising sea levels, the source said.

The officials had been trying to lay the ground for an MEF summit on Thursday that will be chaired by U.S. President Barack Obama and Silvio Berlusconi of Italy, which chairs the G8."